21656086670593 has 4 divisors (see below), whose sum is σ = 21658439834928. Its totient is φ = 21653733506260.

The previous prime is 21656086670573. The next prime is 21656086670627. The reversal of 21656086670593 is 39507668065612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21656086670593 - 2³⁷ = 21518647717121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21656086670573) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1176568363 + ... + 1176586768.

It is an arithmetic number, because the mean of its divisors is an integer number (5414609958732).

Almost surely, 2^{21656086670593} is an apocalyptic number.

It is an amenable number.

21656086670593 is a deficient number, since it is larger than the sum of its proper divisors (2353164335).

21656086670593 is an equidigital number, since it uses as much as digits as its factorization.

21656086670593 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2353164334.

The product of its (nonzero) digits is 97977600, while the sum is 64.

The spelling of 21656086670593 in words is "twenty-one trillion, six hundred fifty-six billion, eighty-six million, six hundred seventy thousand, five hundred ninety-three".